language.rs

   1//! The `language` crate provides a large chunk of Zed's language-related
   2//! features (the other big contributors being project and lsp crates that revolve around LSP features).
   3//! Namely, this crate:
   4//! - Provides [`Language`], [`Grammar`] and [`LanguageRegistry`] types that
   5//!   use Tree-sitter to provide syntax highlighting to the editor; note though that `language` doesn't perform the highlighting by itself. It only maps ranges in a buffer to colors. Treesitter is also used for buffer outlines (lists of symbols in a buffer)
   6//! - Exposes [`LanguageConfig`] that describes how constructs (like brackets or line comments) should be handled by the editor for a source file of a particular language.
   7//!
   8//! Notably we do *not* assign a single language to a single file; in real world a single file can consist of multiple programming languages - HTML is a good example of that - and `language` crate tends to reflect that status quo in its API.
   9mod buffer;
  10mod diagnostic_set;
  11mod highlight_map;
  12mod language_registry;
  13pub mod language_settings;
  14mod outline;
  15pub mod proto;
  16mod syntax_map;
  17mod task_context;
  18mod toolchain;
  19
  20#[cfg(test)]
  21pub mod buffer_tests;
  22pub mod markdown;
  23
  24pub use crate::language_settings::InlineCompletionPreviewMode;
  25use crate::language_settings::SoftWrap;
  26use anyhow::{anyhow, Context as _, Result};
  27use async_trait::async_trait;
  28use collections::{HashMap, HashSet};
  29use fs::Fs;
  30use futures::Future;
  31use gpui::{App, AsyncApp, Entity, SharedString, Task};
  32pub use highlight_map::HighlightMap;
  33use http_client::HttpClient;
  34pub use language_registry::{LanguageName, LoadedLanguage};
  35use lsp::{
  36    CodeActionKind, InitializeParams, LanguageServerBinary, LanguageServerBinaryOptions,
  37    LanguageServerName,
  38};
  39use parking_lot::Mutex;
  40use regex::Regex;
  41use schemars::{
  42    gen::SchemaGenerator,
  43    schema::{InstanceType, Schema, SchemaObject},
  44    JsonSchema,
  45};
  46use serde::{de, Deserialize, Deserializer, Serialize, Serializer};
  47use serde_json::Value;
  48use settings::WorktreeId;
  49use smol::future::FutureExt as _;
  50use std::num::NonZeroU32;
  51use std::{
  52    any::Any,
  53    ffi::OsStr,
  54    fmt::Debug,
  55    hash::Hash,
  56    mem,
  57    ops::{DerefMut, Range},
  58    path::{Path, PathBuf},
  59    pin::Pin,
  60    str,
  61    sync::{
  62        atomic::{AtomicU64, AtomicUsize, Ordering::SeqCst},
  63        Arc, LazyLock,
  64    },
  65};
  66use syntax_map::{QueryCursorHandle, SyntaxSnapshot};
  67use task::RunnableTag;
  68pub use task_context::{ContextProvider, RunnableRange};
  69use theme::SyntaxTheme;
  70pub use toolchain::{LanguageToolchainStore, Toolchain, ToolchainList, ToolchainLister};
  71use tree_sitter::{self, wasmtime, Query, QueryCursor, WasmStore};
  72use util::serde::default_true;
  73
  74pub use buffer::Operation;
  75pub use buffer::*;
  76pub use diagnostic_set::DiagnosticEntry;
  77pub use language_registry::{
  78    AvailableLanguage, LanguageNotFound, LanguageQueries, LanguageRegistry,
  79    LanguageServerBinaryStatus, QUERY_FILENAME_PREFIXES,
  80};
  81pub use lsp::LanguageServerId;
  82pub use outline::*;
  83pub use syntax_map::{OwnedSyntaxLayer, SyntaxLayer, ToTreeSitterPoint, TreeSitterOptions};
  84pub use text::{AnchorRangeExt, LineEnding};
  85pub use tree_sitter::{Node, Parser, Tree, TreeCursor};
  86
  87/// Initializes the `language` crate.
  88///
  89/// This should be called before making use of items from the create.
  90pub fn init(cx: &mut App) {
  91    language_settings::init(cx);
  92}
  93
  94static QUERY_CURSORS: Mutex<Vec<QueryCursor>> = Mutex::new(vec![]);
  95static PARSERS: Mutex<Vec<Parser>> = Mutex::new(vec![]);
  96
  97pub fn with_parser<F, R>(func: F) -> R
  98where
  99    F: FnOnce(&mut Parser) -> R,
 100{
 101    let mut parser = PARSERS.lock().pop().unwrap_or_else(|| {
 102        let mut parser = Parser::new();
 103        parser
 104            .set_wasm_store(WasmStore::new(&WASM_ENGINE).unwrap())
 105            .unwrap();
 106        parser
 107    });
 108    parser.set_included_ranges(&[]).unwrap();
 109    let result = func(&mut parser);
 110    PARSERS.lock().push(parser);
 111    result
 112}
 113
 114pub fn with_query_cursor<F, R>(func: F) -> R
 115where
 116    F: FnOnce(&mut QueryCursor) -> R,
 117{
 118    let mut cursor = QueryCursorHandle::new();
 119    func(cursor.deref_mut())
 120}
 121
 122static NEXT_LANGUAGE_ID: LazyLock<AtomicUsize> = LazyLock::new(Default::default);
 123static NEXT_GRAMMAR_ID: LazyLock<AtomicUsize> = LazyLock::new(Default::default);
 124static WASM_ENGINE: LazyLock<wasmtime::Engine> = LazyLock::new(|| {
 125    wasmtime::Engine::new(&wasmtime::Config::new()).expect("Failed to create Wasmtime engine")
 126});
 127
 128/// A shared grammar for plain text, exposed for reuse by downstream crates.
 129pub static PLAIN_TEXT: LazyLock<Arc<Language>> = LazyLock::new(|| {
 130    Arc::new(Language::new(
 131        LanguageConfig {
 132            name: "Plain Text".into(),
 133            soft_wrap: Some(SoftWrap::EditorWidth),
 134            matcher: LanguageMatcher {
 135                path_suffixes: vec!["txt".to_owned()],
 136                first_line_pattern: None,
 137            },
 138            ..Default::default()
 139        },
 140        None,
 141    ))
 142});
 143
 144/// Types that represent a position in a buffer, and can be converted into
 145/// an LSP position, to send to a language server.
 146pub trait ToLspPosition {
 147    /// Converts the value into an LSP position.
 148    fn to_lsp_position(self) -> lsp::Position;
 149}
 150
 151#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 152pub struct Location {
 153    pub buffer: Entity<Buffer>,
 154    pub range: Range<Anchor>,
 155}
 156
 157/// Represents a Language Server, with certain cached sync properties.
 158/// Uses [`LspAdapter`] under the hood, but calls all 'static' methods
 159/// once at startup, and caches the results.
 160pub struct CachedLspAdapter {
 161    pub name: LanguageServerName,
 162    pub disk_based_diagnostic_sources: Vec<String>,
 163    pub disk_based_diagnostics_progress_token: Option<String>,
 164    language_ids: HashMap<String, String>,
 165    pub adapter: Arc<dyn LspAdapter>,
 166    pub reinstall_attempt_count: AtomicU64,
 167    cached_binary: futures::lock::Mutex<Option<LanguageServerBinary>>,
 168}
 169
 170impl Debug for CachedLspAdapter {
 171    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 172        f.debug_struct("CachedLspAdapter")
 173            .field("name", &self.name)
 174            .field(
 175                "disk_based_diagnostic_sources",
 176                &self.disk_based_diagnostic_sources,
 177            )
 178            .field(
 179                "disk_based_diagnostics_progress_token",
 180                &self.disk_based_diagnostics_progress_token,
 181            )
 182            .field("language_ids", &self.language_ids)
 183            .field("reinstall_attempt_count", &self.reinstall_attempt_count)
 184            .finish_non_exhaustive()
 185    }
 186}
 187
 188impl CachedLspAdapter {
 189    pub fn new(adapter: Arc<dyn LspAdapter>) -> Arc<Self> {
 190        let name = adapter.name();
 191        let disk_based_diagnostic_sources = adapter.disk_based_diagnostic_sources();
 192        let disk_based_diagnostics_progress_token = adapter.disk_based_diagnostics_progress_token();
 193        let language_ids = adapter.language_ids();
 194
 195        Arc::new(CachedLspAdapter {
 196            name,
 197            disk_based_diagnostic_sources,
 198            disk_based_diagnostics_progress_token,
 199            language_ids,
 200            adapter,
 201            cached_binary: Default::default(),
 202            reinstall_attempt_count: AtomicU64::new(0),
 203        })
 204    }
 205
 206    pub fn name(&self) -> LanguageServerName {
 207        self.adapter.name().clone()
 208    }
 209
 210    pub async fn get_language_server_command(
 211        self: Arc<Self>,
 212        delegate: Arc<dyn LspAdapterDelegate>,
 213        toolchains: Arc<dyn LanguageToolchainStore>,
 214        binary_options: LanguageServerBinaryOptions,
 215        cx: &mut AsyncApp,
 216    ) -> Result<LanguageServerBinary> {
 217        let cached_binary = self.cached_binary.lock().await;
 218        self.adapter
 219            .clone()
 220            .get_language_server_command(delegate, toolchains, binary_options, cached_binary, cx)
 221            .await
 222    }
 223
 224    pub fn code_action_kinds(&self) -> Option<Vec<CodeActionKind>> {
 225        self.adapter.code_action_kinds()
 226    }
 227
 228    pub fn process_diagnostics(&self, params: &mut lsp::PublishDiagnosticsParams) {
 229        self.adapter.process_diagnostics(params)
 230    }
 231
 232    pub async fn process_completions(&self, completion_items: &mut [lsp::CompletionItem]) {
 233        self.adapter.process_completions(completion_items).await
 234    }
 235
 236    pub async fn labels_for_completions(
 237        &self,
 238        completion_items: &[lsp::CompletionItem],
 239        language: &Arc<Language>,
 240    ) -> Result<Vec<Option<CodeLabel>>> {
 241        self.adapter
 242            .clone()
 243            .labels_for_completions(completion_items, language)
 244            .await
 245    }
 246
 247    pub async fn labels_for_symbols(
 248        &self,
 249        symbols: &[(String, lsp::SymbolKind)],
 250        language: &Arc<Language>,
 251    ) -> Result<Vec<Option<CodeLabel>>> {
 252        self.adapter
 253            .clone()
 254            .labels_for_symbols(symbols, language)
 255            .await
 256    }
 257
 258    pub fn language_id(&self, language_name: &LanguageName) -> String {
 259        self.language_ids
 260            .get(language_name.as_ref())
 261            .cloned()
 262            .unwrap_or_else(|| language_name.lsp_id())
 263    }
 264}
 265
 266/// [`LspAdapterDelegate`] allows [`LspAdapter]` implementations to interface with the application
 267// e.g. to display a notification or fetch data from the web.
 268#[async_trait]
 269pub trait LspAdapterDelegate: Send + Sync {
 270    fn show_notification(&self, message: &str, cx: &mut App);
 271    fn http_client(&self) -> Arc<dyn HttpClient>;
 272    fn worktree_id(&self) -> WorktreeId;
 273    fn worktree_root_path(&self) -> &Path;
 274    fn update_status(&self, language: LanguageServerName, status: LanguageServerBinaryStatus);
 275    async fn language_server_download_dir(&self, name: &LanguageServerName) -> Option<Arc<Path>>;
 276
 277    async fn npm_package_installed_version(
 278        &self,
 279        package_name: &str,
 280    ) -> Result<Option<(PathBuf, String)>>;
 281    async fn which(&self, command: &OsStr) -> Option<PathBuf>;
 282    async fn shell_env(&self) -> HashMap<String, String>;
 283    async fn read_text_file(&self, path: PathBuf) -> Result<String>;
 284    async fn try_exec(&self, binary: LanguageServerBinary) -> Result<()>;
 285}
 286
 287#[async_trait(?Send)]
 288pub trait LspAdapter: 'static + Send + Sync {
 289    fn name(&self) -> LanguageServerName;
 290
 291    fn get_language_server_command<'a>(
 292        self: Arc<Self>,
 293        delegate: Arc<dyn LspAdapterDelegate>,
 294        toolchains: Arc<dyn LanguageToolchainStore>,
 295        binary_options: LanguageServerBinaryOptions,
 296        mut cached_binary: futures::lock::MutexGuard<'a, Option<LanguageServerBinary>>,
 297        cx: &'a mut AsyncApp,
 298    ) -> Pin<Box<dyn 'a + Future<Output = Result<LanguageServerBinary>>>> {
 299        async move {
 300            // First we check whether the adapter can give us a user-installed binary.
 301            // If so, we do *not* want to cache that, because each worktree might give us a different
 302            // binary:
 303            //
 304            //      worktree 1: user-installed at `.bin/gopls`
 305            //      worktree 2: user-installed at `~/bin/gopls`
 306            //      worktree 3: no gopls found in PATH -> fallback to Zed installation
 307            //
 308            // We only want to cache when we fall back to the global one,
 309            // because we don't want to download and overwrite our global one
 310            // for each worktree we might have open.
 311            if binary_options.allow_path_lookup {
 312                if let Some(binary) = self.check_if_user_installed(delegate.as_ref(), toolchains, cx).await {
 313                    log::info!(
 314                        "found user-installed language server for {}. path: {:?}, arguments: {:?}",
 315                        self.name().0,
 316                        binary.path,
 317                        binary.arguments
 318                    );
 319                    return Ok(binary);
 320                }
 321            }
 322
 323            if !binary_options.allow_binary_download {
 324                return Err(anyhow!("downloading language servers disabled"));
 325            }
 326
 327            if let Some(cached_binary) = cached_binary.as_ref() {
 328                return Ok(cached_binary.clone());
 329            }
 330
 331            let Some(container_dir) = delegate.language_server_download_dir(&self.name()).await else {
 332                anyhow::bail!("no language server download dir defined")
 333            };
 334
 335            let mut binary = try_fetch_server_binary(self.as_ref(), &delegate, container_dir.to_path_buf(), cx).await;
 336
 337            if let Err(error) = binary.as_ref() {
 338                if let Some(prev_downloaded_binary) = self
 339                    .cached_server_binary(container_dir.to_path_buf(), delegate.as_ref())
 340                    .await
 341                {
 342                    log::info!(
 343                        "failed to fetch newest version of language server {:?}. error: {:?}, falling back to using {:?}",
 344                        self.name(),
 345                        error,
 346                        prev_downloaded_binary.path
 347                    );
 348                    binary = Ok(prev_downloaded_binary);
 349                } else {
 350                    delegate.update_status(
 351                        self.name(),
 352                        LanguageServerBinaryStatus::Failed {
 353                            error: format!("{error:?}"),
 354                        },
 355                    );
 356                }
 357            }
 358
 359            if let Ok(binary) = &binary {
 360                *cached_binary = Some(binary.clone());
 361            }
 362
 363            binary
 364        }
 365        .boxed_local()
 366    }
 367
 368    async fn check_if_user_installed(
 369        &self,
 370        _: &dyn LspAdapterDelegate,
 371        _: Arc<dyn LanguageToolchainStore>,
 372        _: &AsyncApp,
 373    ) -> Option<LanguageServerBinary> {
 374        None
 375    }
 376
 377    async fn fetch_latest_server_version(
 378        &self,
 379        delegate: &dyn LspAdapterDelegate,
 380    ) -> Result<Box<dyn 'static + Send + Any>>;
 381
 382    fn will_fetch_server(
 383        &self,
 384        _: &Arc<dyn LspAdapterDelegate>,
 385        _: &mut AsyncApp,
 386    ) -> Option<Task<Result<()>>> {
 387        None
 388    }
 389
 390    async fn check_if_version_installed(
 391        &self,
 392        _version: &(dyn 'static + Send + Any),
 393        _container_dir: &PathBuf,
 394        _delegate: &dyn LspAdapterDelegate,
 395    ) -> Option<LanguageServerBinary> {
 396        None
 397    }
 398
 399    async fn fetch_server_binary(
 400        &self,
 401        latest_version: Box<dyn 'static + Send + Any>,
 402        container_dir: PathBuf,
 403        delegate: &dyn LspAdapterDelegate,
 404    ) -> Result<LanguageServerBinary>;
 405
 406    async fn cached_server_binary(
 407        &self,
 408        container_dir: PathBuf,
 409        delegate: &dyn LspAdapterDelegate,
 410    ) -> Option<LanguageServerBinary>;
 411
 412    fn process_diagnostics(&self, _: &mut lsp::PublishDiagnosticsParams) {}
 413
 414    /// Post-processes completions provided by the language server.
 415    async fn process_completions(&self, _: &mut [lsp::CompletionItem]) {}
 416
 417    async fn labels_for_completions(
 418        self: Arc<Self>,
 419        completions: &[lsp::CompletionItem],
 420        language: &Arc<Language>,
 421    ) -> Result<Vec<Option<CodeLabel>>> {
 422        let mut labels = Vec::new();
 423        for (ix, completion) in completions.iter().enumerate() {
 424            let label = self.label_for_completion(completion, language).await;
 425            if let Some(label) = label {
 426                labels.resize(ix + 1, None);
 427                *labels.last_mut().unwrap() = Some(label);
 428            }
 429        }
 430        Ok(labels)
 431    }
 432
 433    async fn label_for_completion(
 434        &self,
 435        _: &lsp::CompletionItem,
 436        _: &Arc<Language>,
 437    ) -> Option<CodeLabel> {
 438        None
 439    }
 440
 441    async fn labels_for_symbols(
 442        self: Arc<Self>,
 443        symbols: &[(String, lsp::SymbolKind)],
 444        language: &Arc<Language>,
 445    ) -> Result<Vec<Option<CodeLabel>>> {
 446        let mut labels = Vec::new();
 447        for (ix, (name, kind)) in symbols.iter().enumerate() {
 448            let label = self.label_for_symbol(name, *kind, language).await;
 449            if let Some(label) = label {
 450                labels.resize(ix + 1, None);
 451                *labels.last_mut().unwrap() = Some(label);
 452            }
 453        }
 454        Ok(labels)
 455    }
 456
 457    async fn label_for_symbol(
 458        &self,
 459        _: &str,
 460        _: lsp::SymbolKind,
 461        _: &Arc<Language>,
 462    ) -> Option<CodeLabel> {
 463        None
 464    }
 465
 466    /// Returns initialization options that are going to be sent to a LSP server as a part of [`lsp::InitializeParams`]
 467    async fn initialization_options(
 468        self: Arc<Self>,
 469        _: &dyn Fs,
 470        _: &Arc<dyn LspAdapterDelegate>,
 471    ) -> Result<Option<Value>> {
 472        Ok(None)
 473    }
 474
 475    async fn workspace_configuration(
 476        self: Arc<Self>,
 477        _: &dyn Fs,
 478        _: &Arc<dyn LspAdapterDelegate>,
 479        _: Arc<dyn LanguageToolchainStore>,
 480        _cx: &mut AsyncApp,
 481    ) -> Result<Value> {
 482        Ok(serde_json::json!({}))
 483    }
 484
 485    /// Returns a list of code actions supported by a given LspAdapter
 486    fn code_action_kinds(&self) -> Option<Vec<CodeActionKind>> {
 487        Some(vec![
 488            CodeActionKind::EMPTY,
 489            CodeActionKind::QUICKFIX,
 490            CodeActionKind::REFACTOR,
 491            CodeActionKind::REFACTOR_EXTRACT,
 492            CodeActionKind::SOURCE,
 493        ])
 494    }
 495
 496    fn disk_based_diagnostic_sources(&self) -> Vec<String> {
 497        Default::default()
 498    }
 499
 500    fn disk_based_diagnostics_progress_token(&self) -> Option<String> {
 501        None
 502    }
 503
 504    fn language_ids(&self) -> HashMap<String, String> {
 505        Default::default()
 506    }
 507
 508    /// Support custom initialize params.
 509    fn prepare_initialize_params(&self, original: InitializeParams) -> Result<InitializeParams> {
 510        Ok(original)
 511    }
 512}
 513
 514async fn try_fetch_server_binary<L: LspAdapter + 'static + Send + Sync + ?Sized>(
 515    adapter: &L,
 516    delegate: &Arc<dyn LspAdapterDelegate>,
 517    container_dir: PathBuf,
 518    cx: &mut AsyncApp,
 519) -> Result<LanguageServerBinary> {
 520    if let Some(task) = adapter.will_fetch_server(delegate, cx) {
 521        task.await?;
 522    }
 523
 524    let name = adapter.name();
 525    log::info!("fetching latest version of language server {:?}", name.0);
 526    delegate.update_status(name.clone(), LanguageServerBinaryStatus::CheckingForUpdate);
 527
 528    let latest_version = adapter
 529        .fetch_latest_server_version(delegate.as_ref())
 530        .await?;
 531
 532    if let Some(binary) = adapter
 533        .check_if_version_installed(latest_version.as_ref(), &container_dir, delegate.as_ref())
 534        .await
 535    {
 536        log::info!("language server {:?} is already installed", name.0);
 537        delegate.update_status(name.clone(), LanguageServerBinaryStatus::None);
 538        Ok(binary)
 539    } else {
 540        log::info!("downloading language server {:?}", name.0);
 541        delegate.update_status(adapter.name(), LanguageServerBinaryStatus::Downloading);
 542        let binary = adapter
 543            .fetch_server_binary(latest_version, container_dir, delegate.as_ref())
 544            .await;
 545
 546        delegate.update_status(name.clone(), LanguageServerBinaryStatus::None);
 547        binary
 548    }
 549}
 550
 551#[derive(Clone, Debug, Default, PartialEq, Eq)]
 552pub struct CodeLabel {
 553    /// The text to display.
 554    pub text: String,
 555    /// Syntax highlighting runs.
 556    pub runs: Vec<(Range<usize>, HighlightId)>,
 557    /// The portion of the text that should be used in fuzzy filtering.
 558    pub filter_range: Range<usize>,
 559}
 560
 561#[derive(Clone, Deserialize, JsonSchema)]
 562pub struct LanguageConfig {
 563    /// Human-readable name of the language.
 564    pub name: LanguageName,
 565    /// The name of this language for a Markdown code fence block
 566    pub code_fence_block_name: Option<Arc<str>>,
 567    // The name of the grammar in a WASM bundle (experimental).
 568    pub grammar: Option<Arc<str>>,
 569    /// The criteria for matching this language to a given file.
 570    #[serde(flatten)]
 571    pub matcher: LanguageMatcher,
 572    /// List of bracket types in a language.
 573    #[serde(default)]
 574    #[schemars(schema_with = "bracket_pair_config_json_schema")]
 575    pub brackets: BracketPairConfig,
 576    /// If set to true, auto indentation uses last non empty line to determine
 577    /// the indentation level for a new line.
 578    #[serde(default = "auto_indent_using_last_non_empty_line_default")]
 579    pub auto_indent_using_last_non_empty_line: bool,
 580    // Whether indentation of pasted content should be adjusted based on the context.
 581    #[serde(default)]
 582    pub auto_indent_on_paste: Option<bool>,
 583    /// A regex that is used to determine whether the indentation level should be
 584    /// increased in the following line.
 585    #[serde(default, deserialize_with = "deserialize_regex")]
 586    #[schemars(schema_with = "regex_json_schema")]
 587    pub increase_indent_pattern: Option<Regex>,
 588    /// A regex that is used to determine whether the indentation level should be
 589    /// decreased in the following line.
 590    #[serde(default, deserialize_with = "deserialize_regex")]
 591    #[schemars(schema_with = "regex_json_schema")]
 592    pub decrease_indent_pattern: Option<Regex>,
 593    /// A list of characters that trigger the automatic insertion of a closing
 594    /// bracket when they immediately precede the point where an opening
 595    /// bracket is inserted.
 596    #[serde(default)]
 597    pub autoclose_before: String,
 598    /// A placeholder used internally by Semantic Index.
 599    #[serde(default)]
 600    pub collapsed_placeholder: String,
 601    /// A line comment string that is inserted in e.g. `toggle comments` action.
 602    /// A language can have multiple flavours of line comments. All of the provided line comments are
 603    /// used for comment continuations on the next line, but only the first one is used for Editor::ToggleComments.
 604    #[serde(default)]
 605    pub line_comments: Vec<Arc<str>>,
 606    /// Starting and closing characters of a block comment.
 607    #[serde(default)]
 608    pub block_comment: Option<(Arc<str>, Arc<str>)>,
 609    /// A list of language servers that are allowed to run on subranges of a given language.
 610    #[serde(default)]
 611    pub scope_opt_in_language_servers: Vec<LanguageServerName>,
 612    #[serde(default)]
 613    pub overrides: HashMap<String, LanguageConfigOverride>,
 614    /// A list of characters that Zed should treat as word characters for the
 615    /// purpose of features that operate on word boundaries, like 'move to next word end'
 616    /// or a whole-word search in buffer search.
 617    #[serde(default)]
 618    pub word_characters: HashSet<char>,
 619    /// Whether to indent lines using tab characters, as opposed to multiple
 620    /// spaces.
 621    #[serde(default)]
 622    pub hard_tabs: Option<bool>,
 623    /// How many columns a tab should occupy.
 624    #[serde(default)]
 625    pub tab_size: Option<NonZeroU32>,
 626    /// How to soft-wrap long lines of text.
 627    #[serde(default)]
 628    pub soft_wrap: Option<SoftWrap>,
 629    /// The name of a Prettier parser that will be used for this language when no file path is available.
 630    /// If there's a parser name in the language settings, that will be used instead.
 631    #[serde(default)]
 632    pub prettier_parser_name: Option<String>,
 633    /// If true, this language is only for syntax highlighting via an injection into other
 634    /// languages, but should not appear to the user as a distinct language.
 635    #[serde(default)]
 636    pub hidden: bool,
 637}
 638
 639#[derive(Clone, Debug, Serialize, Deserialize, Default, JsonSchema)]
 640pub struct LanguageMatcher {
 641    /// Given a list of `LanguageConfig`'s, the language of a file can be determined based on the path extension matching any of the `path_suffixes`.
 642    #[serde(default)]
 643    pub path_suffixes: Vec<String>,
 644    /// A regex pattern that determines whether the language should be assigned to a file or not.
 645    #[serde(
 646        default,
 647        serialize_with = "serialize_regex",
 648        deserialize_with = "deserialize_regex"
 649    )]
 650    #[schemars(schema_with = "regex_json_schema")]
 651    pub first_line_pattern: Option<Regex>,
 652}
 653
 654/// Represents a language for the given range. Some languages (e.g. HTML)
 655/// interleave several languages together, thus a single buffer might actually contain
 656/// several nested scopes.
 657#[derive(Clone, Debug)]
 658pub struct LanguageScope {
 659    language: Arc<Language>,
 660    override_id: Option<u32>,
 661}
 662
 663#[derive(Clone, Deserialize, Default, Debug, JsonSchema)]
 664pub struct LanguageConfigOverride {
 665    #[serde(default)]
 666    pub line_comments: Override<Vec<Arc<str>>>,
 667    #[serde(default)]
 668    pub block_comment: Override<(Arc<str>, Arc<str>)>,
 669    #[serde(skip)]
 670    pub disabled_bracket_ixs: Vec<u16>,
 671    #[serde(default)]
 672    pub word_characters: Override<HashSet<char>>,
 673    #[serde(default)]
 674    pub opt_into_language_servers: Vec<LanguageServerName>,
 675}
 676
 677#[derive(Clone, Deserialize, Debug, Serialize, JsonSchema)]
 678#[serde(untagged)]
 679pub enum Override<T> {
 680    Remove { remove: bool },
 681    Set(T),
 682}
 683
 684impl<T> Default for Override<T> {
 685    fn default() -> Self {
 686        Override::Remove { remove: false }
 687    }
 688}
 689
 690impl<T> Override<T> {
 691    fn as_option<'a>(this: Option<&'a Self>, original: Option<&'a T>) -> Option<&'a T> {
 692        match this {
 693            Some(Self::Set(value)) => Some(value),
 694            Some(Self::Remove { remove: true }) => None,
 695            Some(Self::Remove { remove: false }) | None => original,
 696        }
 697    }
 698}
 699
 700impl Default for LanguageConfig {
 701    fn default() -> Self {
 702        Self {
 703            name: LanguageName::new(""),
 704            code_fence_block_name: None,
 705            grammar: None,
 706            matcher: LanguageMatcher::default(),
 707            brackets: Default::default(),
 708            auto_indent_using_last_non_empty_line: auto_indent_using_last_non_empty_line_default(),
 709            auto_indent_on_paste: None,
 710            increase_indent_pattern: Default::default(),
 711            decrease_indent_pattern: Default::default(),
 712            autoclose_before: Default::default(),
 713            line_comments: Default::default(),
 714            block_comment: Default::default(),
 715            scope_opt_in_language_servers: Default::default(),
 716            overrides: Default::default(),
 717            word_characters: Default::default(),
 718            collapsed_placeholder: Default::default(),
 719            hard_tabs: None,
 720            tab_size: None,
 721            soft_wrap: None,
 722            prettier_parser_name: None,
 723            hidden: false,
 724        }
 725    }
 726}
 727
 728fn auto_indent_using_last_non_empty_line_default() -> bool {
 729    true
 730}
 731
 732fn deserialize_regex<'de, D: Deserializer<'de>>(d: D) -> Result<Option<Regex>, D::Error> {
 733    let source = Option::<String>::deserialize(d)?;
 734    if let Some(source) = source {
 735        Ok(Some(regex::Regex::new(&source).map_err(de::Error::custom)?))
 736    } else {
 737        Ok(None)
 738    }
 739}
 740
 741fn regex_json_schema(_: &mut SchemaGenerator) -> Schema {
 742    Schema::Object(SchemaObject {
 743        instance_type: Some(InstanceType::String.into()),
 744        ..Default::default()
 745    })
 746}
 747
 748fn serialize_regex<S>(regex: &Option<Regex>, serializer: S) -> Result<S::Ok, S::Error>
 749where
 750    S: Serializer,
 751{
 752    match regex {
 753        Some(regex) => serializer.serialize_str(regex.as_str()),
 754        None => serializer.serialize_none(),
 755    }
 756}
 757
 758#[doc(hidden)]
 759#[cfg(any(test, feature = "test-support"))]
 760pub struct FakeLspAdapter {
 761    pub name: &'static str,
 762    pub initialization_options: Option<Value>,
 763    pub prettier_plugins: Vec<&'static str>,
 764    pub disk_based_diagnostics_progress_token: Option<String>,
 765    pub disk_based_diagnostics_sources: Vec<String>,
 766    pub language_server_binary: LanguageServerBinary,
 767
 768    pub capabilities: lsp::ServerCapabilities,
 769    pub initializer: Option<Box<dyn 'static + Send + Sync + Fn(&mut lsp::FakeLanguageServer)>>,
 770    pub label_for_completion: Option<
 771        Box<
 772            dyn 'static
 773                + Send
 774                + Sync
 775                + Fn(&lsp::CompletionItem, &Arc<Language>) -> Option<CodeLabel>,
 776        >,
 777    >,
 778}
 779
 780/// Configuration of handling bracket pairs for a given language.
 781///
 782/// This struct includes settings for defining which pairs of characters are considered brackets and
 783/// also specifies any language-specific scopes where these pairs should be ignored for bracket matching purposes.
 784#[derive(Clone, Debug, Default, JsonSchema)]
 785pub struct BracketPairConfig {
 786    /// A list of character pairs that should be treated as brackets in the context of a given language.
 787    pub pairs: Vec<BracketPair>,
 788    /// A list of tree-sitter scopes for which a given bracket should not be active.
 789    /// N-th entry in `[Self::disabled_scopes_by_bracket_ix]` contains a list of disabled scopes for an n-th entry in `[Self::pairs]`
 790    #[serde(skip)]
 791    pub disabled_scopes_by_bracket_ix: Vec<Vec<String>>,
 792}
 793
 794fn bracket_pair_config_json_schema(gen: &mut SchemaGenerator) -> Schema {
 795    Option::<Vec<BracketPairContent>>::json_schema(gen)
 796}
 797
 798#[derive(Deserialize, JsonSchema)]
 799pub struct BracketPairContent {
 800    #[serde(flatten)]
 801    pub bracket_pair: BracketPair,
 802    #[serde(default)]
 803    pub not_in: Vec<String>,
 804}
 805
 806impl<'de> Deserialize<'de> for BracketPairConfig {
 807    fn deserialize<D>(deserializer: D) -> std::result::Result<Self, D::Error>
 808    where
 809        D: Deserializer<'de>,
 810    {
 811        let result = Vec::<BracketPairContent>::deserialize(deserializer)?;
 812        let mut brackets = Vec::with_capacity(result.len());
 813        let mut disabled_scopes_by_bracket_ix = Vec::with_capacity(result.len());
 814        for entry in result {
 815            brackets.push(entry.bracket_pair);
 816            disabled_scopes_by_bracket_ix.push(entry.not_in);
 817        }
 818
 819        Ok(BracketPairConfig {
 820            pairs: brackets,
 821            disabled_scopes_by_bracket_ix,
 822        })
 823    }
 824}
 825
 826/// Describes a single bracket pair and how an editor should react to e.g. inserting
 827/// an opening bracket or to a newline character insertion in between `start` and `end` characters.
 828#[derive(Clone, Debug, Default, Deserialize, PartialEq, JsonSchema)]
 829pub struct BracketPair {
 830    /// Starting substring for a bracket.
 831    pub start: String,
 832    /// Ending substring for a bracket.
 833    pub end: String,
 834    /// True if `end` should be automatically inserted right after `start` characters.
 835    pub close: bool,
 836    /// True if selected text should be surrounded by `start` and `end` characters.
 837    #[serde(default = "default_true")]
 838    pub surround: bool,
 839    /// True if an extra newline should be inserted while the cursor is in the middle
 840    /// of that bracket pair.
 841    pub newline: bool,
 842}
 843
 844#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Copy)]
 845pub(crate) struct LanguageId(usize);
 846
 847impl LanguageId {
 848    pub(crate) fn new() -> Self {
 849        Self(NEXT_LANGUAGE_ID.fetch_add(1, SeqCst))
 850    }
 851}
 852
 853pub struct Language {
 854    pub(crate) id: LanguageId,
 855    pub(crate) config: LanguageConfig,
 856    pub(crate) grammar: Option<Arc<Grammar>>,
 857    pub(crate) context_provider: Option<Arc<dyn ContextProvider>>,
 858    pub(crate) toolchain: Option<Arc<dyn ToolchainLister>>,
 859}
 860
 861#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Copy)]
 862pub struct GrammarId(pub usize);
 863
 864impl GrammarId {
 865    pub(crate) fn new() -> Self {
 866        Self(NEXT_GRAMMAR_ID.fetch_add(1, SeqCst))
 867    }
 868}
 869
 870pub struct Grammar {
 871    id: GrammarId,
 872    pub ts_language: tree_sitter::Language,
 873    pub(crate) error_query: Query,
 874    pub(crate) highlights_query: Option<Query>,
 875    pub(crate) brackets_config: Option<BracketConfig>,
 876    pub(crate) redactions_config: Option<RedactionConfig>,
 877    pub(crate) runnable_config: Option<RunnableConfig>,
 878    pub(crate) indents_config: Option<IndentConfig>,
 879    pub outline_config: Option<OutlineConfig>,
 880    pub text_object_config: Option<TextObjectConfig>,
 881    pub embedding_config: Option<EmbeddingConfig>,
 882    pub(crate) injection_config: Option<InjectionConfig>,
 883    pub(crate) override_config: Option<OverrideConfig>,
 884    pub(crate) highlight_map: Mutex<HighlightMap>,
 885}
 886
 887struct IndentConfig {
 888    query: Query,
 889    indent_capture_ix: u32,
 890    start_capture_ix: Option<u32>,
 891    end_capture_ix: Option<u32>,
 892    outdent_capture_ix: Option<u32>,
 893}
 894
 895pub struct OutlineConfig {
 896    pub query: Query,
 897    pub item_capture_ix: u32,
 898    pub name_capture_ix: u32,
 899    pub context_capture_ix: Option<u32>,
 900    pub extra_context_capture_ix: Option<u32>,
 901    pub open_capture_ix: Option<u32>,
 902    pub close_capture_ix: Option<u32>,
 903    pub annotation_capture_ix: Option<u32>,
 904}
 905
 906#[derive(Debug, Clone, Copy, PartialEq)]
 907pub enum TextObject {
 908    InsideFunction,
 909    AroundFunction,
 910    InsideClass,
 911    AroundClass,
 912    InsideComment,
 913    AroundComment,
 914}
 915
 916impl TextObject {
 917    pub fn from_capture_name(name: &str) -> Option<TextObject> {
 918        match name {
 919            "function.inside" => Some(TextObject::InsideFunction),
 920            "function.around" => Some(TextObject::AroundFunction),
 921            "class.inside" => Some(TextObject::InsideClass),
 922            "class.around" => Some(TextObject::AroundClass),
 923            "comment.inside" => Some(TextObject::InsideComment),
 924            "comment.around" => Some(TextObject::AroundComment),
 925            _ => None,
 926        }
 927    }
 928
 929    pub fn around(&self) -> Option<Self> {
 930        match self {
 931            TextObject::InsideFunction => Some(TextObject::AroundFunction),
 932            TextObject::InsideClass => Some(TextObject::AroundClass),
 933            TextObject::InsideComment => Some(TextObject::AroundComment),
 934            _ => None,
 935        }
 936    }
 937}
 938
 939pub struct TextObjectConfig {
 940    pub query: Query,
 941    pub text_objects_by_capture_ix: Vec<(u32, TextObject)>,
 942}
 943
 944#[derive(Debug)]
 945pub struct EmbeddingConfig {
 946    pub query: Query,
 947    pub item_capture_ix: u32,
 948    pub name_capture_ix: Option<u32>,
 949    pub context_capture_ix: Option<u32>,
 950    pub collapse_capture_ix: Option<u32>,
 951    pub keep_capture_ix: Option<u32>,
 952}
 953
 954struct InjectionConfig {
 955    query: Query,
 956    content_capture_ix: u32,
 957    language_capture_ix: Option<u32>,
 958    patterns: Vec<InjectionPatternConfig>,
 959}
 960
 961struct RedactionConfig {
 962    pub query: Query,
 963    pub redaction_capture_ix: u32,
 964}
 965
 966#[derive(Clone, Debug, PartialEq)]
 967enum RunnableCapture {
 968    Named(SharedString),
 969    Run,
 970}
 971
 972struct RunnableConfig {
 973    pub query: Query,
 974    /// A mapping from capture indice to capture kind
 975    pub extra_captures: Vec<RunnableCapture>,
 976}
 977
 978struct OverrideConfig {
 979    query: Query,
 980    values: HashMap<u32, OverrideEntry>,
 981}
 982
 983#[derive(Debug)]
 984struct OverrideEntry {
 985    name: String,
 986    range_is_inclusive: bool,
 987    value: LanguageConfigOverride,
 988}
 989
 990#[derive(Default, Clone)]
 991struct InjectionPatternConfig {
 992    language: Option<Box<str>>,
 993    combined: bool,
 994}
 995
 996struct BracketConfig {
 997    query: Query,
 998    open_capture_ix: u32,
 999    close_capture_ix: u32,
1000}
1001
1002impl Language {
1003    pub fn new(config: LanguageConfig, ts_language: Option<tree_sitter::Language>) -> Self {
1004        Self::new_with_id(LanguageId::new(), config, ts_language)
1005    }
1006
1007    fn new_with_id(
1008        id: LanguageId,
1009        config: LanguageConfig,
1010        ts_language: Option<tree_sitter::Language>,
1011    ) -> Self {
1012        Self {
1013            id,
1014            config,
1015            grammar: ts_language.map(|ts_language| {
1016                Arc::new(Grammar {
1017                    id: GrammarId::new(),
1018                    highlights_query: None,
1019                    brackets_config: None,
1020                    outline_config: None,
1021                    text_object_config: None,
1022                    embedding_config: None,
1023                    indents_config: None,
1024                    injection_config: None,
1025                    override_config: None,
1026                    redactions_config: None,
1027                    runnable_config: None,
1028                    error_query: Query::new(&ts_language, "(ERROR) @error").unwrap(),
1029                    ts_language,
1030                    highlight_map: Default::default(),
1031                })
1032            }),
1033            context_provider: None,
1034            toolchain: None,
1035        }
1036    }
1037
1038    pub fn with_context_provider(mut self, provider: Option<Arc<dyn ContextProvider>>) -> Self {
1039        self.context_provider = provider;
1040        self
1041    }
1042
1043    pub fn with_toolchain_lister(mut self, provider: Option<Arc<dyn ToolchainLister>>) -> Self {
1044        self.toolchain = provider;
1045        self
1046    }
1047
1048    pub fn with_queries(mut self, queries: LanguageQueries) -> Result<Self> {
1049        if let Some(query) = queries.highlights {
1050            self = self
1051                .with_highlights_query(query.as_ref())
1052                .context("Error loading highlights query")?;
1053        }
1054        if let Some(query) = queries.brackets {
1055            self = self
1056                .with_brackets_query(query.as_ref())
1057                .context("Error loading brackets query")?;
1058        }
1059        if let Some(query) = queries.indents {
1060            self = self
1061                .with_indents_query(query.as_ref())
1062                .context("Error loading indents query")?;
1063        }
1064        if let Some(query) = queries.outline {
1065            self = self
1066                .with_outline_query(query.as_ref())
1067                .context("Error loading outline query")?;
1068        }
1069        if let Some(query) = queries.embedding {
1070            self = self
1071                .with_embedding_query(query.as_ref())
1072                .context("Error loading embedding query")?;
1073        }
1074        if let Some(query) = queries.injections {
1075            self = self
1076                .with_injection_query(query.as_ref())
1077                .context("Error loading injection query")?;
1078        }
1079        if let Some(query) = queries.overrides {
1080            self = self
1081                .with_override_query(query.as_ref())
1082                .context("Error loading override query")?;
1083        }
1084        if let Some(query) = queries.redactions {
1085            self = self
1086                .with_redaction_query(query.as_ref())
1087                .context("Error loading redaction query")?;
1088        }
1089        if let Some(query) = queries.runnables {
1090            self = self
1091                .with_runnable_query(query.as_ref())
1092                .context("Error loading runnables query")?;
1093        }
1094        if let Some(query) = queries.text_objects {
1095            self = self
1096                .with_text_object_query(query.as_ref())
1097                .context("Error loading textobject query")?;
1098        }
1099        Ok(self)
1100    }
1101
1102    pub fn with_highlights_query(mut self, source: &str) -> Result<Self> {
1103        let grammar = self
1104            .grammar_mut()
1105            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1106        grammar.highlights_query = Some(Query::new(&grammar.ts_language, source)?);
1107        Ok(self)
1108    }
1109
1110    pub fn with_runnable_query(mut self, source: &str) -> Result<Self> {
1111        let grammar = self
1112            .grammar_mut()
1113            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1114
1115        let query = Query::new(&grammar.ts_language, source)?;
1116        let mut extra_captures = Vec::with_capacity(query.capture_names().len());
1117
1118        for name in query.capture_names().iter() {
1119            let kind = if *name == "run" {
1120                RunnableCapture::Run
1121            } else {
1122                RunnableCapture::Named(name.to_string().into())
1123            };
1124            extra_captures.push(kind);
1125        }
1126
1127        grammar.runnable_config = Some(RunnableConfig {
1128            extra_captures,
1129            query,
1130        });
1131
1132        Ok(self)
1133    }
1134
1135    pub fn with_outline_query(mut self, source: &str) -> Result<Self> {
1136        let grammar = self
1137            .grammar_mut()
1138            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1139        let query = Query::new(&grammar.ts_language, source)?;
1140        let mut item_capture_ix = None;
1141        let mut name_capture_ix = None;
1142        let mut context_capture_ix = None;
1143        let mut extra_context_capture_ix = None;
1144        let mut open_capture_ix = None;
1145        let mut close_capture_ix = None;
1146        let mut annotation_capture_ix = None;
1147        get_capture_indices(
1148            &query,
1149            &mut [
1150                ("item", &mut item_capture_ix),
1151                ("name", &mut name_capture_ix),
1152                ("context", &mut context_capture_ix),
1153                ("context.extra", &mut extra_context_capture_ix),
1154                ("open", &mut open_capture_ix),
1155                ("close", &mut close_capture_ix),
1156                ("annotation", &mut annotation_capture_ix),
1157            ],
1158        );
1159        if let Some((item_capture_ix, name_capture_ix)) = item_capture_ix.zip(name_capture_ix) {
1160            grammar.outline_config = Some(OutlineConfig {
1161                query,
1162                item_capture_ix,
1163                name_capture_ix,
1164                context_capture_ix,
1165                extra_context_capture_ix,
1166                open_capture_ix,
1167                close_capture_ix,
1168                annotation_capture_ix,
1169            });
1170        }
1171        Ok(self)
1172    }
1173
1174    pub fn with_text_object_query(mut self, source: &str) -> Result<Self> {
1175        let grammar = self
1176            .grammar_mut()
1177            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1178        let query = Query::new(&grammar.ts_language, source)?;
1179
1180        let mut text_objects_by_capture_ix = Vec::new();
1181        for (ix, name) in query.capture_names().iter().enumerate() {
1182            if let Some(text_object) = TextObject::from_capture_name(name) {
1183                text_objects_by_capture_ix.push((ix as u32, text_object));
1184            }
1185        }
1186
1187        grammar.text_object_config = Some(TextObjectConfig {
1188            query,
1189            text_objects_by_capture_ix,
1190        });
1191        Ok(self)
1192    }
1193
1194    pub fn with_embedding_query(mut self, source: &str) -> Result<Self> {
1195        let grammar = self
1196            .grammar_mut()
1197            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1198        let query = Query::new(&grammar.ts_language, source)?;
1199        let mut item_capture_ix = None;
1200        let mut name_capture_ix = None;
1201        let mut context_capture_ix = None;
1202        let mut collapse_capture_ix = None;
1203        let mut keep_capture_ix = None;
1204        get_capture_indices(
1205            &query,
1206            &mut [
1207                ("item", &mut item_capture_ix),
1208                ("name", &mut name_capture_ix),
1209                ("context", &mut context_capture_ix),
1210                ("keep", &mut keep_capture_ix),
1211                ("collapse", &mut collapse_capture_ix),
1212            ],
1213        );
1214        if let Some(item_capture_ix) = item_capture_ix {
1215            grammar.embedding_config = Some(EmbeddingConfig {
1216                query,
1217                item_capture_ix,
1218                name_capture_ix,
1219                context_capture_ix,
1220                collapse_capture_ix,
1221                keep_capture_ix,
1222            });
1223        }
1224        Ok(self)
1225    }
1226
1227    pub fn with_brackets_query(mut self, source: &str) -> Result<Self> {
1228        let grammar = self
1229            .grammar_mut()
1230            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1231        let query = Query::new(&grammar.ts_language, source)?;
1232        let mut open_capture_ix = None;
1233        let mut close_capture_ix = None;
1234        get_capture_indices(
1235            &query,
1236            &mut [
1237                ("open", &mut open_capture_ix),
1238                ("close", &mut close_capture_ix),
1239            ],
1240        );
1241        if let Some((open_capture_ix, close_capture_ix)) = open_capture_ix.zip(close_capture_ix) {
1242            grammar.brackets_config = Some(BracketConfig {
1243                query,
1244                open_capture_ix,
1245                close_capture_ix,
1246            });
1247        }
1248        Ok(self)
1249    }
1250
1251    pub fn with_indents_query(mut self, source: &str) -> Result<Self> {
1252        let grammar = self
1253            .grammar_mut()
1254            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1255        let query = Query::new(&grammar.ts_language, source)?;
1256        let mut indent_capture_ix = None;
1257        let mut start_capture_ix = None;
1258        let mut end_capture_ix = None;
1259        let mut outdent_capture_ix = None;
1260        get_capture_indices(
1261            &query,
1262            &mut [
1263                ("indent", &mut indent_capture_ix),
1264                ("start", &mut start_capture_ix),
1265                ("end", &mut end_capture_ix),
1266                ("outdent", &mut outdent_capture_ix),
1267            ],
1268        );
1269        if let Some(indent_capture_ix) = indent_capture_ix {
1270            grammar.indents_config = Some(IndentConfig {
1271                query,
1272                indent_capture_ix,
1273                start_capture_ix,
1274                end_capture_ix,
1275                outdent_capture_ix,
1276            });
1277        }
1278        Ok(self)
1279    }
1280
1281    pub fn with_injection_query(mut self, source: &str) -> Result<Self> {
1282        let grammar = self
1283            .grammar_mut()
1284            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1285        let query = Query::new(&grammar.ts_language, source)?;
1286        let mut language_capture_ix = None;
1287        let mut injection_language_capture_ix = None;
1288        let mut content_capture_ix = None;
1289        let mut injection_content_capture_ix = None;
1290        get_capture_indices(
1291            &query,
1292            &mut [
1293                ("language", &mut language_capture_ix),
1294                ("injection.language", &mut injection_language_capture_ix),
1295                ("content", &mut content_capture_ix),
1296                ("injection.content", &mut injection_content_capture_ix),
1297            ],
1298        );
1299        language_capture_ix = match (language_capture_ix, injection_language_capture_ix) {
1300            (None, Some(ix)) => Some(ix),
1301            (Some(_), Some(_)) => {
1302                return Err(anyhow!(
1303                    "both language and injection.language captures are present"
1304                ));
1305            }
1306            _ => language_capture_ix,
1307        };
1308        content_capture_ix = match (content_capture_ix, injection_content_capture_ix) {
1309            (None, Some(ix)) => Some(ix),
1310            (Some(_), Some(_)) => {
1311                return Err(anyhow!(
1312                    "both content and injection.content captures are present"
1313                ));
1314            }
1315            _ => content_capture_ix,
1316        };
1317        let patterns = (0..query.pattern_count())
1318            .map(|ix| {
1319                let mut config = InjectionPatternConfig::default();
1320                for setting in query.property_settings(ix) {
1321                    match setting.key.as_ref() {
1322                        "language" | "injection.language" => {
1323                            config.language.clone_from(&setting.value);
1324                        }
1325                        "combined" | "injection.combined" => {
1326                            config.combined = true;
1327                        }
1328                        _ => {}
1329                    }
1330                }
1331                config
1332            })
1333            .collect();
1334        if let Some(content_capture_ix) = content_capture_ix {
1335            grammar.injection_config = Some(InjectionConfig {
1336                query,
1337                language_capture_ix,
1338                content_capture_ix,
1339                patterns,
1340            });
1341        }
1342        Ok(self)
1343    }
1344
1345    pub fn with_override_query(mut self, source: &str) -> anyhow::Result<Self> {
1346        let query = {
1347            let grammar = self
1348                .grammar
1349                .as_ref()
1350                .ok_or_else(|| anyhow!("no grammar for language"))?;
1351            Query::new(&grammar.ts_language, source)?
1352        };
1353
1354        let mut override_configs_by_id = HashMap::default();
1355        for (ix, mut name) in query.capture_names().iter().copied().enumerate() {
1356            let mut range_is_inclusive = false;
1357            if name.starts_with('_') {
1358                continue;
1359            }
1360            if let Some(prefix) = name.strip_suffix(".inclusive") {
1361                name = prefix;
1362                range_is_inclusive = true;
1363            }
1364
1365            let value = self.config.overrides.get(name).cloned().unwrap_or_default();
1366            for server_name in &value.opt_into_language_servers {
1367                if !self
1368                    .config
1369                    .scope_opt_in_language_servers
1370                    .contains(server_name)
1371                {
1372                    util::debug_panic!("Server {server_name:?} has been opted-in by scope {name:?} but has not been marked as an opt-in server");
1373                }
1374            }
1375
1376            override_configs_by_id.insert(
1377                ix as u32,
1378                OverrideEntry {
1379                    name: name.to_string(),
1380                    range_is_inclusive,
1381                    value,
1382                },
1383            );
1384        }
1385
1386        let referenced_override_names = self.config.overrides.keys().chain(
1387            self.config
1388                .brackets
1389                .disabled_scopes_by_bracket_ix
1390                .iter()
1391                .flatten(),
1392        );
1393
1394        for referenced_name in referenced_override_names {
1395            if !override_configs_by_id
1396                .values()
1397                .any(|entry| entry.name == *referenced_name)
1398            {
1399                Err(anyhow!(
1400                    "language {:?} has overrides in config not in query: {referenced_name:?}",
1401                    self.config.name
1402                ))?;
1403            }
1404        }
1405
1406        for entry in override_configs_by_id.values_mut() {
1407            entry.value.disabled_bracket_ixs = self
1408                .config
1409                .brackets
1410                .disabled_scopes_by_bracket_ix
1411                .iter()
1412                .enumerate()
1413                .filter_map(|(ix, disabled_scope_names)| {
1414                    if disabled_scope_names.contains(&entry.name) {
1415                        Some(ix as u16)
1416                    } else {
1417                        None
1418                    }
1419                })
1420                .collect();
1421        }
1422
1423        self.config.brackets.disabled_scopes_by_bracket_ix.clear();
1424
1425        let grammar = self
1426            .grammar_mut()
1427            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1428        grammar.override_config = Some(OverrideConfig {
1429            query,
1430            values: override_configs_by_id,
1431        });
1432        Ok(self)
1433    }
1434
1435    pub fn with_redaction_query(mut self, source: &str) -> anyhow::Result<Self> {
1436        let grammar = self
1437            .grammar_mut()
1438            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1439
1440        let query = Query::new(&grammar.ts_language, source)?;
1441        let mut redaction_capture_ix = None;
1442        get_capture_indices(&query, &mut [("redact", &mut redaction_capture_ix)]);
1443
1444        if let Some(redaction_capture_ix) = redaction_capture_ix {
1445            grammar.redactions_config = Some(RedactionConfig {
1446                query,
1447                redaction_capture_ix,
1448            });
1449        }
1450
1451        Ok(self)
1452    }
1453
1454    fn grammar_mut(&mut self) -> Option<&mut Grammar> {
1455        Arc::get_mut(self.grammar.as_mut()?)
1456    }
1457
1458    pub fn name(&self) -> LanguageName {
1459        self.config.name.clone()
1460    }
1461
1462    pub fn code_fence_block_name(&self) -> Arc<str> {
1463        self.config
1464            .code_fence_block_name
1465            .clone()
1466            .unwrap_or_else(|| self.config.name.as_ref().to_lowercase().into())
1467    }
1468
1469    pub fn context_provider(&self) -> Option<Arc<dyn ContextProvider>> {
1470        self.context_provider.clone()
1471    }
1472
1473    pub fn toolchain_lister(&self) -> Option<Arc<dyn ToolchainLister>> {
1474        self.toolchain.clone()
1475    }
1476
1477    pub fn highlight_text<'a>(
1478        self: &'a Arc<Self>,
1479        text: &'a Rope,
1480        range: Range<usize>,
1481    ) -> Vec<(Range<usize>, HighlightId)> {
1482        let mut result = Vec::new();
1483        if let Some(grammar) = &self.grammar {
1484            let tree = grammar.parse_text(text, None);
1485            let captures =
1486                SyntaxSnapshot::single_tree_captures(range.clone(), text, &tree, self, |grammar| {
1487                    grammar.highlights_query.as_ref()
1488                });
1489            let highlight_maps = vec![grammar.highlight_map()];
1490            let mut offset = 0;
1491            for chunk in
1492                BufferChunks::new(text, range, Some((captures, highlight_maps)), false, None)
1493            {
1494                let end_offset = offset + chunk.text.len();
1495                if let Some(highlight_id) = chunk.syntax_highlight_id {
1496                    if !highlight_id.is_default() {
1497                        result.push((offset..end_offset, highlight_id));
1498                    }
1499                }
1500                offset = end_offset;
1501            }
1502        }
1503        result
1504    }
1505
1506    pub fn path_suffixes(&self) -> &[String] {
1507        &self.config.matcher.path_suffixes
1508    }
1509
1510    pub fn should_autoclose_before(&self, c: char) -> bool {
1511        c.is_whitespace() || self.config.autoclose_before.contains(c)
1512    }
1513
1514    pub fn set_theme(&self, theme: &SyntaxTheme) {
1515        if let Some(grammar) = self.grammar.as_ref() {
1516            if let Some(highlights_query) = &grammar.highlights_query {
1517                *grammar.highlight_map.lock() =
1518                    HighlightMap::new(highlights_query.capture_names(), theme);
1519            }
1520        }
1521    }
1522
1523    pub fn grammar(&self) -> Option<&Arc<Grammar>> {
1524        self.grammar.as_ref()
1525    }
1526
1527    pub fn default_scope(self: &Arc<Self>) -> LanguageScope {
1528        LanguageScope {
1529            language: self.clone(),
1530            override_id: None,
1531        }
1532    }
1533
1534    pub fn lsp_id(&self) -> String {
1535        self.config.name.lsp_id()
1536    }
1537
1538    pub fn prettier_parser_name(&self) -> Option<&str> {
1539        self.config.prettier_parser_name.as_deref()
1540    }
1541
1542    pub fn config(&self) -> &LanguageConfig {
1543        &self.config
1544    }
1545}
1546
1547impl LanguageScope {
1548    pub fn path_suffixes(&self) -> &[String] {
1549        &self.language.path_suffixes()
1550    }
1551
1552    pub fn language_name(&self) -> LanguageName {
1553        self.language.config.name.clone()
1554    }
1555
1556    pub fn collapsed_placeholder(&self) -> &str {
1557        self.language.config.collapsed_placeholder.as_ref()
1558    }
1559
1560    /// Returns line prefix that is inserted in e.g. line continuations or
1561    /// in `toggle comments` action.
1562    pub fn line_comment_prefixes(&self) -> &[Arc<str>] {
1563        Override::as_option(
1564            self.config_override().map(|o| &o.line_comments),
1565            Some(&self.language.config.line_comments),
1566        )
1567        .map_or([].as_slice(), |e| e.as_slice())
1568    }
1569
1570    pub fn block_comment_delimiters(&self) -> Option<(&Arc<str>, &Arc<str>)> {
1571        Override::as_option(
1572            self.config_override().map(|o| &o.block_comment),
1573            self.language.config.block_comment.as_ref(),
1574        )
1575        .map(|e| (&e.0, &e.1))
1576    }
1577
1578    /// Returns a list of language-specific word characters.
1579    ///
1580    /// By default, Zed treats alphanumeric characters (and '_') as word characters for
1581    /// the purpose of actions like 'move to next word end` or whole-word search.
1582    /// It additionally accounts for language's additional word characters.
1583    pub fn word_characters(&self) -> Option<&HashSet<char>> {
1584        Override::as_option(
1585            self.config_override().map(|o| &o.word_characters),
1586            Some(&self.language.config.word_characters),
1587        )
1588    }
1589
1590    /// Returns a list of bracket pairs for a given language with an additional
1591    /// piece of information about whether the particular bracket pair is currently active for a given language.
1592    pub fn brackets(&self) -> impl Iterator<Item = (&BracketPair, bool)> {
1593        let mut disabled_ids = self
1594            .config_override()
1595            .map_or(&[] as _, |o| o.disabled_bracket_ixs.as_slice());
1596        self.language
1597            .config
1598            .brackets
1599            .pairs
1600            .iter()
1601            .enumerate()
1602            .map(move |(ix, bracket)| {
1603                let mut is_enabled = true;
1604                if let Some(next_disabled_ix) = disabled_ids.first() {
1605                    if ix == *next_disabled_ix as usize {
1606                        disabled_ids = &disabled_ids[1..];
1607                        is_enabled = false;
1608                    }
1609                }
1610                (bracket, is_enabled)
1611            })
1612    }
1613
1614    pub fn should_autoclose_before(&self, c: char) -> bool {
1615        c.is_whitespace() || self.language.config.autoclose_before.contains(c)
1616    }
1617
1618    pub fn language_allowed(&self, name: &LanguageServerName) -> bool {
1619        let config = &self.language.config;
1620        let opt_in_servers = &config.scope_opt_in_language_servers;
1621        if opt_in_servers.iter().any(|o| *o == *name) {
1622            if let Some(over) = self.config_override() {
1623                over.opt_into_language_servers.iter().any(|o| *o == *name)
1624            } else {
1625                false
1626            }
1627        } else {
1628            true
1629        }
1630    }
1631
1632    pub fn override_name(&self) -> Option<&str> {
1633        let id = self.override_id?;
1634        let grammar = self.language.grammar.as_ref()?;
1635        let override_config = grammar.override_config.as_ref()?;
1636        override_config.values.get(&id).map(|e| e.name.as_str())
1637    }
1638
1639    fn config_override(&self) -> Option<&LanguageConfigOverride> {
1640        let id = self.override_id?;
1641        let grammar = self.language.grammar.as_ref()?;
1642        let override_config = grammar.override_config.as_ref()?;
1643        override_config.values.get(&id).map(|e| &e.value)
1644    }
1645}
1646
1647impl Hash for Language {
1648    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
1649        self.id.hash(state)
1650    }
1651}
1652
1653impl PartialEq for Language {
1654    fn eq(&self, other: &Self) -> bool {
1655        self.id.eq(&other.id)
1656    }
1657}
1658
1659impl Eq for Language {}
1660
1661impl Debug for Language {
1662    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
1663        f.debug_struct("Language")
1664            .field("name", &self.config.name)
1665            .finish()
1666    }
1667}
1668
1669impl Grammar {
1670    pub fn id(&self) -> GrammarId {
1671        self.id
1672    }
1673
1674    fn parse_text(&self, text: &Rope, old_tree: Option<Tree>) -> Tree {
1675        with_parser(|parser| {
1676            parser
1677                .set_language(&self.ts_language)
1678                .expect("incompatible grammar");
1679            let mut chunks = text.chunks_in_range(0..text.len());
1680            parser
1681                .parse_with(
1682                    &mut move |offset, _| {
1683                        chunks.seek(offset);
1684                        chunks.next().unwrap_or("").as_bytes()
1685                    },
1686                    old_tree.as_ref(),
1687                )
1688                .unwrap()
1689        })
1690    }
1691
1692    pub fn highlight_map(&self) -> HighlightMap {
1693        self.highlight_map.lock().clone()
1694    }
1695
1696    pub fn highlight_id_for_name(&self, name: &str) -> Option<HighlightId> {
1697        let capture_id = self
1698            .highlights_query
1699            .as_ref()?
1700            .capture_index_for_name(name)?;
1701        Some(self.highlight_map.lock().get(capture_id))
1702    }
1703}
1704
1705impl CodeLabel {
1706    pub fn fallback_for_completion(
1707        item: &lsp::CompletionItem,
1708        language: Option<&Language>,
1709    ) -> Self {
1710        let highlight_id = item.kind.and_then(|kind| {
1711            let grammar = language?.grammar()?;
1712            use lsp::CompletionItemKind as Kind;
1713            match kind {
1714                Kind::CLASS => grammar.highlight_id_for_name("type"),
1715                Kind::CONSTANT => grammar.highlight_id_for_name("constant"),
1716                Kind::CONSTRUCTOR => grammar.highlight_id_for_name("constructor"),
1717                Kind::ENUM => grammar
1718                    .highlight_id_for_name("enum")
1719                    .or_else(|| grammar.highlight_id_for_name("type")),
1720                Kind::FIELD => grammar.highlight_id_for_name("property"),
1721                Kind::FUNCTION => grammar.highlight_id_for_name("function"),
1722                Kind::INTERFACE => grammar.highlight_id_for_name("type"),
1723                Kind::METHOD => grammar
1724                    .highlight_id_for_name("function.method")
1725                    .or_else(|| grammar.highlight_id_for_name("function")),
1726                Kind::OPERATOR => grammar.highlight_id_for_name("operator"),
1727                Kind::PROPERTY => grammar.highlight_id_for_name("property"),
1728                Kind::STRUCT => grammar.highlight_id_for_name("type"),
1729                Kind::VARIABLE => grammar.highlight_id_for_name("variable"),
1730                Kind::KEYWORD => grammar.highlight_id_for_name("keyword"),
1731                _ => None,
1732            }
1733        });
1734
1735        let label = &item.label;
1736        let label_length = label.len();
1737        let runs = highlight_id
1738            .map(|highlight_id| vec![(0..label_length, highlight_id)])
1739            .unwrap_or_default();
1740        let text = if let Some(detail) = &item.detail {
1741            format!("{label} {detail}")
1742        } else if let Some(description) = item
1743            .label_details
1744            .as_ref()
1745            .and_then(|label_details| label_details.description.as_ref())
1746        {
1747            format!("{label} {description}")
1748        } else {
1749            label.clone()
1750        };
1751        Self {
1752            text,
1753            runs,
1754            filter_range: 0..label_length,
1755        }
1756    }
1757
1758    pub fn plain(text: String, filter_text: Option<&str>) -> Self {
1759        let mut result = Self {
1760            runs: Vec::new(),
1761            filter_range: 0..text.len(),
1762            text,
1763        };
1764        if let Some(filter_text) = filter_text {
1765            if let Some(ix) = result.text.find(filter_text) {
1766                result.filter_range = ix..ix + filter_text.len();
1767            }
1768        }
1769        result
1770    }
1771
1772    pub fn push_str(&mut self, text: &str, highlight: Option<HighlightId>) {
1773        let start_ix = self.text.len();
1774        self.text.push_str(text);
1775        let end_ix = self.text.len();
1776        if let Some(highlight) = highlight {
1777            self.runs.push((start_ix..end_ix, highlight));
1778        }
1779    }
1780
1781    pub fn text(&self) -> &str {
1782        self.text.as_str()
1783    }
1784
1785    pub fn filter_text(&self) -> &str {
1786        &self.text[self.filter_range.clone()]
1787    }
1788}
1789
1790impl From<String> for CodeLabel {
1791    fn from(value: String) -> Self {
1792        Self::plain(value, None)
1793    }
1794}
1795
1796impl From<&str> for CodeLabel {
1797    fn from(value: &str) -> Self {
1798        Self::plain(value.to_string(), None)
1799    }
1800}
1801
1802impl Ord for LanguageMatcher {
1803    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
1804        self.path_suffixes.cmp(&other.path_suffixes).then_with(|| {
1805            self.first_line_pattern
1806                .as_ref()
1807                .map(Regex::as_str)
1808                .cmp(&other.first_line_pattern.as_ref().map(Regex::as_str))
1809        })
1810    }
1811}
1812
1813impl PartialOrd for LanguageMatcher {
1814    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
1815        Some(self.cmp(other))
1816    }
1817}
1818
1819impl Eq for LanguageMatcher {}
1820
1821impl PartialEq for LanguageMatcher {
1822    fn eq(&self, other: &Self) -> bool {
1823        self.path_suffixes == other.path_suffixes
1824            && self.first_line_pattern.as_ref().map(Regex::as_str)
1825                == other.first_line_pattern.as_ref().map(Regex::as_str)
1826    }
1827}
1828
1829#[cfg(any(test, feature = "test-support"))]
1830impl Default for FakeLspAdapter {
1831    fn default() -> Self {
1832        Self {
1833            name: "the-fake-language-server",
1834            capabilities: lsp::LanguageServer::full_capabilities(),
1835            initializer: None,
1836            disk_based_diagnostics_progress_token: None,
1837            initialization_options: None,
1838            disk_based_diagnostics_sources: Vec::new(),
1839            prettier_plugins: Vec::new(),
1840            language_server_binary: LanguageServerBinary {
1841                path: "/the/fake/lsp/path".into(),
1842                arguments: vec![],
1843                env: Default::default(),
1844            },
1845            label_for_completion: None,
1846        }
1847    }
1848}
1849
1850#[cfg(any(test, feature = "test-support"))]
1851#[async_trait(?Send)]
1852impl LspAdapter for FakeLspAdapter {
1853    fn name(&self) -> LanguageServerName {
1854        LanguageServerName(self.name.into())
1855    }
1856
1857    async fn check_if_user_installed(
1858        &self,
1859        _: &dyn LspAdapterDelegate,
1860        _: Arc<dyn LanguageToolchainStore>,
1861        _: &AsyncApp,
1862    ) -> Option<LanguageServerBinary> {
1863        Some(self.language_server_binary.clone())
1864    }
1865
1866    fn get_language_server_command<'a>(
1867        self: Arc<Self>,
1868        _: Arc<dyn LspAdapterDelegate>,
1869        _: Arc<dyn LanguageToolchainStore>,
1870        _: LanguageServerBinaryOptions,
1871        _: futures::lock::MutexGuard<'a, Option<LanguageServerBinary>>,
1872        _: &'a mut AsyncApp,
1873    ) -> Pin<Box<dyn 'a + Future<Output = Result<LanguageServerBinary>>>> {
1874        async move { Ok(self.language_server_binary.clone()) }.boxed_local()
1875    }
1876
1877    async fn fetch_latest_server_version(
1878        &self,
1879        _: &dyn LspAdapterDelegate,
1880    ) -> Result<Box<dyn 'static + Send + Any>> {
1881        unreachable!();
1882    }
1883
1884    async fn fetch_server_binary(
1885        &self,
1886        _: Box<dyn 'static + Send + Any>,
1887        _: PathBuf,
1888        _: &dyn LspAdapterDelegate,
1889    ) -> Result<LanguageServerBinary> {
1890        unreachable!();
1891    }
1892
1893    async fn cached_server_binary(
1894        &self,
1895        _: PathBuf,
1896        _: &dyn LspAdapterDelegate,
1897    ) -> Option<LanguageServerBinary> {
1898        unreachable!();
1899    }
1900
1901    fn process_diagnostics(&self, _: &mut lsp::PublishDiagnosticsParams) {}
1902
1903    fn disk_based_diagnostic_sources(&self) -> Vec<String> {
1904        self.disk_based_diagnostics_sources.clone()
1905    }
1906
1907    fn disk_based_diagnostics_progress_token(&self) -> Option<String> {
1908        self.disk_based_diagnostics_progress_token.clone()
1909    }
1910
1911    async fn initialization_options(
1912        self: Arc<Self>,
1913        _: &dyn Fs,
1914        _: &Arc<dyn LspAdapterDelegate>,
1915    ) -> Result<Option<Value>> {
1916        Ok(self.initialization_options.clone())
1917    }
1918
1919    async fn label_for_completion(
1920        &self,
1921        item: &lsp::CompletionItem,
1922        language: &Arc<Language>,
1923    ) -> Option<CodeLabel> {
1924        let label_for_completion = self.label_for_completion.as_ref()?;
1925        label_for_completion(item, language)
1926    }
1927}
1928
1929fn get_capture_indices(query: &Query, captures: &mut [(&str, &mut Option<u32>)]) {
1930    for (ix, name) in query.capture_names().iter().enumerate() {
1931        for (capture_name, index) in captures.iter_mut() {
1932            if capture_name == name {
1933                **index = Some(ix as u32);
1934                break;
1935            }
1936        }
1937    }
1938}
1939
1940pub fn point_to_lsp(point: PointUtf16) -> lsp::Position {
1941    lsp::Position::new(point.row, point.column)
1942}
1943
1944pub fn point_from_lsp(point: lsp::Position) -> Unclipped<PointUtf16> {
1945    Unclipped(PointUtf16::new(point.line, point.character))
1946}
1947
1948pub fn range_to_lsp(range: Range<PointUtf16>) -> Result<lsp::Range> {
1949    if range.start > range.end {
1950        Err(anyhow!(
1951            "Inverted range provided to an LSP request: {:?}-{:?}",
1952            range.start,
1953            range.end
1954        ))
1955    } else {
1956        Ok(lsp::Range {
1957            start: point_to_lsp(range.start),
1958            end: point_to_lsp(range.end),
1959        })
1960    }
1961}
1962
1963pub fn range_from_lsp(range: lsp::Range) -> Range<Unclipped<PointUtf16>> {
1964    let mut start = point_from_lsp(range.start);
1965    let mut end = point_from_lsp(range.end);
1966    if start > end {
1967        log::warn!("range_from_lsp called with inverted range {start:?}-{end:?}");
1968        mem::swap(&mut start, &mut end);
1969    }
1970    start..end
1971}
1972
1973#[cfg(test)]
1974mod tests {
1975    use super::*;
1976    use gpui::TestAppContext;
1977
1978    #[gpui::test(iterations = 10)]
1979    async fn test_language_loading(cx: &mut TestAppContext) {
1980        let languages = LanguageRegistry::test(cx.executor());
1981        let languages = Arc::new(languages);
1982        languages.register_native_grammars([
1983            ("json", tree_sitter_json::LANGUAGE),
1984            ("rust", tree_sitter_rust::LANGUAGE),
1985        ]);
1986        languages.register_test_language(LanguageConfig {
1987            name: "JSON".into(),
1988            grammar: Some("json".into()),
1989            matcher: LanguageMatcher {
1990                path_suffixes: vec!["json".into()],
1991                ..Default::default()
1992            },
1993            ..Default::default()
1994        });
1995        languages.register_test_language(LanguageConfig {
1996            name: "Rust".into(),
1997            grammar: Some("rust".into()),
1998            matcher: LanguageMatcher {
1999                path_suffixes: vec!["rs".into()],
2000                ..Default::default()
2001            },
2002            ..Default::default()
2003        });
2004        assert_eq!(
2005            languages.language_names(),
2006            &[
2007                "JSON".to_string(),
2008                "Plain Text".to_string(),
2009                "Rust".to_string(),
2010            ]
2011        );
2012
2013        let rust1 = languages.language_for_name("Rust");
2014        let rust2 = languages.language_for_name("Rust");
2015
2016        // Ensure language is still listed even if it's being loaded.
2017        assert_eq!(
2018            languages.language_names(),
2019            &[
2020                "JSON".to_string(),
2021                "Plain Text".to_string(),
2022                "Rust".to_string(),
2023            ]
2024        );
2025
2026        let (rust1, rust2) = futures::join!(rust1, rust2);
2027        assert!(Arc::ptr_eq(&rust1.unwrap(), &rust2.unwrap()));
2028
2029        // Ensure language is still listed even after loading it.
2030        assert_eq!(
2031            languages.language_names(),
2032            &[
2033                "JSON".to_string(),
2034                "Plain Text".to_string(),
2035                "Rust".to_string(),
2036            ]
2037        );
2038
2039        // Loading an unknown language returns an error.
2040        assert!(languages.language_for_name("Unknown").await.is_err());
2041    }
2042}